Update Contact

Update an existing contact's information. Only the fields you include in the request body will be updated — all other fields remain unchanged.

Endpoint

PATCH /contacts/:id

Returns: 200 OK

Headers

Header	Value	Required
`Authorization`	`Bearer <your-api-key>`	Yes
`Content-Type`	`application/json`	Yes

Path Parameters

Parameter	Type	Description
`id`	string	The contact ID to update

Body Parameters

All fields are optional. Only include the fields you want to change.

Parameter	Type	Required	Description
`email`	string \| null	No	Updated email address. Set to `null` to clear.
`phone_number`	string \| null	No	Updated phone number in E.164 format. Set to `null` to clear.
`external_id`	string \| null	No	Your own identifier for this person. Max 255 characters, unique within your organization — reusing another contact's returns `409`. Set to `null` to clear.
`first_name`	string \| null	No	Updated first name. Max 100 characters. Set to `null` to clear.
`last_name`	string \| null	No	Updated last name. Max 100 characters. Set to `null` to clear.
`properties`	object	No	Custom property values. Replaces the previous values.
`list_ids`	string[]	No	Replaces the contact's list membership with exactly these lists — it is not additive. Send `[]` to remove the contact from every list; omit the field to leave membership untouched.

info

Setting a field to null clears its value. Omitting a field leaves it unchanged. These are different behaviors — be intentional about which you use.

Response

Returns the full updated contact object. See Create Contact for the complete response schema.

{
  "id": "01957e3a-4b5c-7d8e-9f0a-1b2c3d4e5f6a",
  "email": "john.updated@example.com",
  "phone_number": "+201234567890",
  "external_id": "user_10294",
  "first_name": "John",
  "last_name": "Doe",
  "source": "api",
  "properties": {
    "company": "New Company"
  },
  "is_suppressed": false,
  "created_at": "2026-01-15T10:00:00.000Z",
  "updated_at": "2026-03-08T14:30:00.000Z"
}

Examples

Update Email and Name

cURL
JavaScript
Python
C#
PHP

curl -X PATCH "https://api.arsel.sa/v1/contacts/01957e3a-4b5c-7d8e-9f0a-1b2c3d4e5f6a" \
  -H "Authorization: Bearer $ARSEL_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
    "email": "john.updated@example.com",
    "first_name": "Jonathan"
  }'

const response = await fetch("https://api.arsel.sa/v1/contacts/01957e3a-4b5c-7d8e-9f0a-1b2c3d4e5f6a", {
  method: "PATCH",
  headers: {
    Authorization: `Bearer ${process.env.ARSEL_API_KEY}`,
    "Content-Type": "application/json",
  },
  body: JSON.stringify({
    email: "john.updated@example.com",
    first_name: "Jonathan",
  }),
});

const data = await response.json();
if (!response.ok) {
  throw new Error(`${data.name}: ${data.message}`);
}

console.log(data);

import os

import requests

response = requests.patch(
    "https://api.arsel.sa/v1/contacts/01957e3a-4b5c-7d8e-9f0a-1b2c3d4e5f6a",
    headers={"Authorization": f"Bearer {os.environ['ARSEL_API_KEY']}"},
    json={
        "email": "john.updated@example.com",
        "first_name": "Jonathan",
    },
)
response.raise_for_status()

print(response.json())

using System.Net.Http.Headers;
using System.Text;

var client = new HttpClient(); // share one instance across requests
client.DefaultRequestHeaders.Authorization = new AuthenticationHeaderValue(
    "Bearer", Environment.GetEnvironmentVariable("ARSEL_API_KEY"));

var request = new HttpRequestMessage(HttpMethod.Patch, "https://api.arsel.sa/v1/contacts/01957e3a-4b5c-7d8e-9f0a-1b2c3d4e5f6a")
{
    Content = new StringContent(
        """
        {
          "email": "john.updated@example.com",
          "first_name": "Jonathan"
        }
        """,
        Encoding.UTF8,
        "application/json"),
};

var response = await client.SendAsync(request);
var body = await response.Content.ReadAsStringAsync();
if (!response.IsSuccessStatusCode)
    throw new HttpRequestException($"{(int)response.StatusCode}: {body}");

Console.WriteLine(body);

<?php
$ch = curl_init("https://api.arsel.sa/v1/contacts/01957e3a-4b5c-7d8e-9f0a-1b2c3d4e5f6a");
curl_setopt_array($ch, [
    CURLOPT_RETURNTRANSFER => true,
    CURLOPT_CUSTOMREQUEST => "PATCH",
    CURLOPT_HTTPHEADER => [
        "Authorization: Bearer " . getenv("ARSEL_API_KEY"),
        "Content-Type: application/json",
    ],
    CURLOPT_POSTFIELDS => json_encode([
        "email" => "john.updated@example.com",
        "first_name" => "Jonathan",
    ]),
]);

$data = json_decode(curl_exec($ch), true);
if (curl_getinfo($ch, CURLINFO_HTTP_CODE) >= 400) {
    throw new Exception("{$data['name']}: {$data['message']}");
}

print_r($data);

Update Custom Properties

cURL
JavaScript
Python
C#
PHP

curl -X PATCH "https://api.arsel.sa/v1/contacts/01957e3a-4b5c-7d8e-9f0a-1b2c3d4e5f6a" \
  -H "Authorization: Bearer $ARSEL_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
    "properties": {
      "company": "New Company",
      "city": "Jeddah"
    }
  }'

const response = await fetch("https://api.arsel.sa/v1/contacts/01957e3a-4b5c-7d8e-9f0a-1b2c3d4e5f6a", {
  method: "PATCH",
  headers: {
    Authorization: `Bearer ${process.env.ARSEL_API_KEY}`,
    "Content-Type": "application/json",
  },
  body: JSON.stringify({
    properties: {
      company: "New Company",
      city: "Jeddah",
    },
  }),
});

const data = await response.json();
if (!response.ok) {
  throw new Error(`${data.name}: ${data.message}`);
}

console.log(data);

import os

import requests

response = requests.patch(
    "https://api.arsel.sa/v1/contacts/01957e3a-4b5c-7d8e-9f0a-1b2c3d4e5f6a",
    headers={"Authorization": f"Bearer {os.environ['ARSEL_API_KEY']}"},
    json={
        "properties": {
            "company": "New Company",
            "city": "Jeddah",
        },
    },
)
response.raise_for_status()

print(response.json())

using System.Net.Http.Headers;
using System.Text;

var client = new HttpClient(); // share one instance across requests
client.DefaultRequestHeaders.Authorization = new AuthenticationHeaderValue(
    "Bearer", Environment.GetEnvironmentVariable("ARSEL_API_KEY"));

var request = new HttpRequestMessage(HttpMethod.Patch, "https://api.arsel.sa/v1/contacts/01957e3a-4b5c-7d8e-9f0a-1b2c3d4e5f6a")
{
    Content = new StringContent(
        """
        {
          "properties": {
            "company": "New Company",
            "city": "Jeddah"
          }
        }
        """,
        Encoding.UTF8,
        "application/json"),
};

var response = await client.SendAsync(request);
var body = await response.Content.ReadAsStringAsync();
if (!response.IsSuccessStatusCode)
    throw new HttpRequestException($"{(int)response.StatusCode}: {body}");

Console.WriteLine(body);

<?php
$ch = curl_init("https://api.arsel.sa/v1/contacts/01957e3a-4b5c-7d8e-9f0a-1b2c3d4e5f6a");
curl_setopt_array($ch, [
    CURLOPT_RETURNTRANSFER => true,
    CURLOPT_CUSTOMREQUEST => "PATCH",
    CURLOPT_HTTPHEADER => [
        "Authorization: Bearer " . getenv("ARSEL_API_KEY"),
        "Content-Type: application/json",
    ],
    CURLOPT_POSTFIELDS => json_encode([
        "properties" => [
            "company" => "New Company",
            "city" => "Jeddah",
        ],
    ]),
]);

$data = json_decode(curl_exec($ch), true);
if (curl_getinfo($ch, CURLINFO_HTTP_CODE) >= 400) {
    throw new Exception("{$data['name']}: {$data['message']}");
}

print_r($data);

Error Responses

422 Validation Error
409 Conflict
404 Not Found
401 Unauthorized

{
  "status_code": 422,
  "name": "validation_error",
  "message": "email must be an email"
}

{
  "status_code": 409,
  "name": "conflict",
  "message": "A contact with this email already exists in your organization"
}

{
  "status_code": 404,
  "name": "not_found",
  "message": "Contact not found"
}

{
  "status_code": 401,
  "name": "unauthorized",
  "message": "Invalid API Key"
}

Endpoint​

Headers​

Path Parameters​

Body Parameters​

Response​

Examples​

Update Email and Name​

Update Custom Properties​

Error Responses​